[brilliantcode]

He's not wrong, backtesting really is not the same as testing on real live data. You are fitting your models on data that has already been done, without any of the risks factored in. Even if you do find a system that picks every ups and downs in the backtest, it will do poorly with live trades because the volatility and risk is something that changes based on fundamental data.

However, in this case, the fact that no backtest or any sort of risk/reward ratios were published suggests high level of skepticism.

tl;dr: past prices can't predict future prices.